arch/openrisc/include/asm/futex.h

   1 #ifndef __ASM_OPENRISC_FUTEX_H
   2 #define __ASM_OPENRISC_FUTEX_H
   3
   4 #ifdef __KERNEL__
   5
   6 #include <linux/futex.h>
   7 #include <linux/uaccess.h>
   8 #include <asm/errno.h>
   9
  10 #define __futex_atomic_op(insn, ret, oldval, uaddr, oparg) \
  11 ({                                                              \
  12         __asm__ __volatile__ (                                  \
  13                 "1:     l.lwa   %0, %2                  \n"     \
  14                         insn                            "\n"    \
  15                 "2:     l.swa   %2, %1                  \n"     \
  16                 "       l.bnf   1b                      \n"     \
  17                 "        l.ori  %1, r0, 0               \n"     \
  18                 "3:                                     \n"     \
  19                 ".section .fixup,\"ax\"                 \n"     \
  20                 "4:     l.j     3b                      \n"     \
  21                 "        l.addi %1, r0, %3              \n"     \
  22                 ".previous                              \n"     \
  23                 ".section __ex_table,\"a\"              \n"     \
  24                 ".word  1b,4b,2b,4b                     \n"     \
  25                 ".previous                              \n"     \
  26                 : "=&r" (oldval), "=&r" (ret), "+m" (*uaddr)    \
  27                 : "i" (-EFAULT), "r" (oparg)                    \
  28                 : "cc", "memory"                                \
  29                 );                                              \
  30 })
  31
  32 static inline int
  33 futex_atomic_op_inuser(int encoded_op, u32 __user *uaddr)
  34 {
  35         int op = (encoded_op >> 28) & 7;
  36         int cmp = (encoded_op >> 24) & 15;
  37         int oparg = (encoded_op << 8) >> 20;
  38         int cmparg = (encoded_op << 20) >> 20;
  39         int oldval = 0, ret;
  40
  41         if (encoded_op & (FUTEX_OP_OPARG_SHIFT << 28))
  42                 oparg = 1 << oparg;
  43
  44         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
  45                 return -EFAULT;
  46
  47         pagefault_disable();
  48
  49         switch (op) {
  50         case FUTEX_OP_SET:
  51                 __futex_atomic_op("l.or %1,%4,%4", ret, oldval, uaddr, oparg);
  52                 break;
  53         case FUTEX_OP_ADD:
  54                 __futex_atomic_op("l.add %1,%0,%4", ret, oldval, uaddr, oparg);
  55                 break;
  56         case FUTEX_OP_OR:
  57                 __futex_atomic_op("l.or %1,%0,%4", ret, oldval, uaddr, oparg);
  58                 break;
  59         case FUTEX_OP_ANDN:
  60                 __futex_atomic_op("l.and %1,%0,%4", ret, oldval, uaddr, ~oparg);
  61                 break;
  62         case FUTEX_OP_XOR:
  63                 __futex_atomic_op("l.xor %1,%0,%4", ret, oldval, uaddr, oparg);
  64                 break;
  65         default:
  66                 ret = -ENOSYS;
  67         }
  68
  69         pagefault_enable();
  70
  71         if (!ret) {
  72                 switch (cmp) {
  73                 case FUTEX_OP_CMP_EQ:
  74                         ret = (oldval == cmparg);
  75                         break;
  76                 case FUTEX_OP_CMP_NE:
  77                         ret = (oldval != cmparg);
  78                         break;
  79                 case FUTEX_OP_CMP_LT:
  80                         ret = (oldval < cmparg);
  81                         break;
  82                 case FUTEX_OP_CMP_GE:
  83                         ret = (oldval >= cmparg);
  84                         break;
  85                 case FUTEX_OP_CMP_LE:
  86                         ret = (oldval <= cmparg);
  87                         break;
  88                 case FUTEX_OP_CMP_GT:
  89                         ret = (oldval > cmparg);
  90                         break;
  91                 default:
  92                         ret = -ENOSYS;
  93                 }
  94         }
  95         return ret;
  96 }
  97
  98 static inline int
  99 futex_atomic_cmpxchg_inatomic(u32 *uval, u32 __user *uaddr,
 100                               u32 oldval, u32 newval)
 101 {
 102         int ret = 0;
 103         u32 prev;
 104
 105         if (!access_ok(VERIFY_WRITE, uaddr, sizeof(u32)))
 106                 return -EFAULT;
 107
 108         __asm__ __volatile__ (                          \
 109                 "1:     l.lwa   %1, %2          \n"     \
 110                 "       l.sfeq  %1, %3          \n"     \
 111                 "       l.bnf   3f              \n"     \
 112                 "        l.nop                  \n"     \
 113                 "2:     l.swa   %2, %4          \n"     \
 114                 "       l.bnf   1b              \n"     \
 115                 "        l.nop                  \n"     \
 116                 "3:                             \n"     \
 117                 ".section .fixup,\"ax\"         \n"     \
 118                 "4:     l.j     3b              \n"     \
 119                 "        l.addi %0, r0, %5      \n"     \
 120                 ".previous                      \n"     \
 121                 ".section __ex_table,\"a\"      \n"     \
 122                 ".word  1b,4b,2b,4b             \n"     \
 123                 ".previous                      \n"     \
 124                 : "+r" (ret), "=&r" (prev), "+m" (*uaddr) \
 125                 : "r" (oldval), "r" (newval), "i" (-EFAULT) \
 126                 : "cc", "memory"                        \
 127                 );
 128
 129         *uval = prev;
 130         return ret;
 131 }
 132
 133 #endif /* __KERNEL__ */
 134
 135 #endif /* __ASM_OPENRISC_FUTEX_H */